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How to Extract Fossils

Fossils are a record of Earth's history imprinted within rocks. Fossils form when a creature dies and its remains are then buried or preserved by environmental conditions. Over time, the creature decays and its body is gradually replaced by other minerals in the soil. These minerals harden over the course of millions of years into fossilized imprints of the creature. Scientists have two primary methods of extracting fossils from rock--mechanical extraction and acid extraction.

Things You'll Need

Hammer
Chisel
Pneumatic air pen
Microscope
Drill
Needle
Acetic acid

Instructions

Mechanical Extraction
- 1
  Clean the fossil as well as you can by brushing off excess dirt and rinsing the fossil, if you believe you can do so without breaking it.
- 2
  Remove large pieces of rock surrounding the fossil using a hammer and chisel. Do not get too close to the fossil.
- 3
  Use a pneumatic air pen to slowly chisel away the pieces of rock closest to the fossil itself. A pneumatic air pen is a specialty tool most often used for inscribing hard surfaces such as metal. Apply very minimal pressure as the air pen vibrates 30,000 times each minute and you do not want to damage the fossil.
- 4
  Place the section of the sample you are working on under a microscope. Use a small drill fitted with a diamond tip to slowly drill away at the remainder of the surrounding rock.
- 5
  Pick away any flecks of rock that remain attached to the fossil with a needle.
Acid Extraction
- 6
  Place the fossilized remains into a solution containing 5 percent acetic acid. This will gradually erode the surface of the surrounding rock.
- 7
  Leave the fossil within the acid mixture for approximately one to three days.
- 8
  Place the fossilized rock section beneath running water. The fossil needs to remain within the water for three times the amount of time that it was exposed to the acid.
- 9
  Dry the specimen carefully and repeat the process. Over time the acid mixture will remove the rock surrounding the fossil. Acid extraction can take months or years to be complete.

Rocks & Minerals